This invention is directed to photographic materials comprising light-sensitive silver halide emulsions and, in particular, to stabilized silver halide emulsions which have less tendency to fog, and with little or no sacrifice of other sensitometry properties such as gradient, Dmax, and speed.
Gelatin-silver halide emulsions are subject to fogging, which may be defined as a uniform deposit of silver extending over and either partially or wholly obliterating the image. Fog may be caused in a number of ways, as for example, by excessive ripening of the emulsion, by storage of the light-sensitive element at elevated temperatures, and humidity, or by prolonged development of the exposed emulsion.
A great number of antifogging and stabilizing agents have been recommended in the literature for the purpose of preventing the formation of fog in light-sensitive silver halide emulsions. Although these compounds have the ability to control fog during manufacture, as well as during storage, many of these compounds adversely affect other sensitometric properties such as speed, gradient and Dmax. It is, accordingly, an object of this invention to provide a light-sensitive emulsion which has a reduced tendency to fog but at the same time retains a good balance of other sensitometric properties.